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Any way to disable the warning screen on nuvi 2599 with firmware 8.50 (HWID 1947).
How do you find what changes should be applied in firmware?

Download the latest or desired firmware and open it in RGN tool to extract out the fw_all.bin. Use IDA Pro to disassemble the fw_all.bin file. Locate the timeout function and patch so it times out in one millisecond. Depending on firmware another approach may need to be taken.

Thanks for your reply. Could you provide a little more help? I have never used IDA Pro before and I'm lost in its data. I have loaded and disassembled my firmware but I have no idea what to do from this point.
How could I locate the appropriate function and wha tto do after locating it?

In briefly looking at your firmware, it looks similar to the firmware for the Garmin Infotainment unit. They both use boost functions which I am still trying to understand. You could patch the jumptable to make case 7 (loc_2B03B8) jump to the default case as I did for the infotainment but it would likely have undesired side effects like disabling phone functionality. In case you want to try it out, patch at file offset 0x2701F7 from 0xE3 to 0x72 to make case 7 jump to default case.

In briefly looking at your firmware, it looks similar to the firmware for the Garmin Infotainment unit. They both use boost functions which I am still trying to understand. You could patch the jumptable to make case 7 (loc_2B03B8) jump to the default case as I did for the infotainment but it would likely have undesired side effects like disabling phone functionality. In case you want to try it out, patch at file offset 0x2701F7 from 0xE3 to 0x72 to make case 7 jump to default case.

How long does the warning screen display before timing out?

Ignore all that. The reason it looked similar is I accidentally extracted fw_all.bin from the infotainment gcd and it was of course identical. Woops.

It appears our warning page function is at sub_207541A0. This skips it and other stuff in one instance where it is being called. There are other places that call it so it may skip the warning only when there are no EULAs to agree to or on some other condition. It may also crash at startup, or have no noticeable effect. I have not looked in detail yet at the firmware.

sub_2070AA44 appears to fetch the string referenced by the dword in R1 so the following line sets up R1 to cause the "Agree" string to be loaded by sub_2070AA44.

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